HOW TO EXTRACT HTTP STATUS FROM GRAPH API

Question

HOW TO EXTRACT HTTP STATUS FROM GRAPH API

Giorgio Sfiligoi 371

When a Graph API encounters an error, how can I extract the HTTP status code in C#?

Rukmini 1,171 Reputation points Microsoft External Staff

2025-04-21T03:22:43.2366667+00:00

@Giorgio Sfiligoi, We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, please respond with more details and we will try to help

2 answers

Your answer

Rukmini 1,171 Reputation points Microsoft External Staff

2025-04-21T03:22:43.2366667+00:00

@Giorgio Sfiligoi, We haven’t heard from you on the last response and was just checking back to see if you have a resolution yet. In case if you have any resolution, please do share that same with the community as it can be helpful to others. Otherwise, please respond with more details and we will try to help

Answer 1

Bruce (SqlWork.com) 74,451

I assume use are using the graph sdk and not the rest api. See docs for getting the response code:

https://github.com/microsoftgraph/msgraph-sdk-dotnet/blob/main/docs/errors.md

Giorgio Sfiligoi 371

You are absolutely right, I am using Graph SDK.

But I am puzzled - consider the following piece of code:

        try
        {
            // Upload the file
            var uploadResult = await fileUploadTask.UploadAsync(progress);

            sb.AppendLine(uploadResult.UploadSucceeded
                ? $"Upload complete, item ID: {uploadResult.ItemResponse.Id}" 
                : "Upload failed");
        }
        catch (ODataError ex)
        {
            sb.AppendLine($"ODataError uploading: {ex.Error?.Message}");
            sb.AppendLine($"StatusCode: {ex.ResponseStatusCode}");
        }
        catch(ServiceException ex)
        { 
            sb.AppendLine($"Service exception: {ex.Message}");
            sb.AppendLine($"StatusCode: {ex.ResponseStatusCode}");
        }
        catch (HttpRequestException ex)
        {
            sb.AppendLine($"HttpException: {ex.Message}");
            sb.AppendLine($"HttpRequestError: {ex.HttpRequestError}");
            sb.AppendLine($"StatusCode: {ex.StatusCode}");
        }
        catch (Exception ex)
        {
            sb.AppendLine(ex.Message);
        }
        finally
        {
            result.Text = sb.ToString();
        }

If I disconnect the Internet connection while it is uploading the file, it throws HttpRequestException with

Message: An error occurred while sending the request,

HttpRequestError = 0 (unknown),

StatusCode = null

Shouldn't it throw ODataError?

Answer 2

Hello @Giorgio Sfiligoi, Since you're using the Microsoft Graph SDK, you're likely expecting exceptions like ODataError or ServiceException when something goes wrong. However, if the internet connection is lost during the request, the SDK throws an HttpRequestException instead — and in this case, StatusCode will be null, and HttpRequestError is marked as Unknown.

ODataError is thrown only when the Microsoft Graph API returns a valid HTTP response that includes a structured OData error in the body — for instance, errors like 400 Bad Request, 403 Forbidden, or 404 Not Found.
ServiceException is a more general error from the Graph SDK that wraps any error responses received from the API. It includes useful details like the HTTP status code and error message.
HttpRequestException, on the other hand, comes from the underlying System.Net.Http layer. It’s thrown when the request fails before it ever reaches the Microsoft Graph service — for example, due to network issues, DNS problems, or no internet connection. Since there's no HTTP response in these cases, there’s no status code available.

So, in your case, ODataError wasn’t throw because both ODataError and ServiceException depend on the existence of a valid HTTP response from Microsoft Graph. If the network is disconnected and the request can’t reach the service at all, no response is received — and therefore, no structured error can be parsed. ODataError is typically used when there is a response body to analyze, which doesn't apply in this scenario.

Hence, The HttpRequestException is the correct exception to handle in this scenario, and it indicates a problem with the request itself rather than a server-side error.

Hope this clarifies things!

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If you have any other questions or are still experiencing issues, feel free to ask in the "comments" section, and I'd be happy to help.

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HOW TO EXTRACT HTTP STATUS FROM GRAPH API

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